The present invention relates to a base station for protecting a predetermined area from disturbing usage of mobile terminals of a wireless cellular telecommunication system, to a method for protecting a predetermined area from disturbing usage of mobile terminals of a wireless cellular telecommunication system and to a mobile terminal for a wireless cellular telecommunication system.
In many areas the use of mobile terminals of wireless telecommunication systems is regarded as a nuisance for other people, like in restaurants or in the opera, or even dangerous in places like hospitals or airplanes. In the first case particularly audible signals output from mobile terminals are disturbing other people or the spectacle being given. In the second case, the use of mobile terminals, particularly the transmission of high frequency electromagnetic waves, can disturb other electronic devices or the like by interfering with their circuitry what can lead to severe incidents. It is therefore very important to provide a way to protect predetermined areas from a disturbing usage of mobile terminals within these areas. Particularly, the protection of a predetermined area should not depend on the user""s will, e. g. on a user""s input of information to the mobile terminal.
EP 0 891 110 A1 discloses a method and a system for preventing a mobile terminal from causing disturbance within a predetermined area, e. g. inside a plane or inside of hospitals. Particularly, the disclosed method comprises the steps of transmitting a deactivation signal from a base station to a mobile terminal and deactivating a use of the output of the mobile terminal in response to the deactivation signal. Thereby, the transmission output is deactivated. The base station can either be an ordinary base station or a base station specifically designed for mainly transmitting the deactivation signal. Although EP 0 891 110 A1 describes, that the base station could be an ordinary base station, it is not disclosed how the deactivation signals could be implemented and transmitted in an ordinary telecommunication system.
The object of the present invention is therefore to provide a base station and a method for protecting a predetermined area from disturbing usage of mobile terminals of a wireless cellular telecommunication system, which protects a predetermined area by transmitting mode change information for changing an operation mode of the mobile terminals in a simple and effective way, whereby the mode change information is transmitted on the basis of a wireless cellular telecommunication system. The object of the present invention is further to provide a mobile terminal for a wireless cellular telecommunication system, which can be controlled by such mode change information so that the predetermined area is protected from disturbing use of the mobile terminal.
The above object is achieved by a base station for protecting a predetermined area from disturbing usage of mobile terminals of a wireless cellular telecommunication system, with generating means for generating mode change information for changing an operation mode of the mobile terminals to protect the predetermined area, and transmitting means for transmitting said generated mode change information within said predetermined area by means of system information messages of a broadcast control channel of a wireless telecommunication system.
The above object is further achieved by a method for protecting a predetermined area from disturbing usage of mobile terminals of a wireless cellular telecommunication system, with the steps of generating mode change information for changing an operation mode of the mobile terminals to protect the predetermined area, and transmitting said generated mode change information within said predetermined area by means of system information messages of a broadcast control channel of a wireless telecommunication system.
Thus, the base station and the method for protecting a predetermined area from disturbing usage of mobile terminals of a wireless cellular telecommunication system enable a simple and effective way to change the operation mode of mobile terminals within the predetermined area automatically so that the predetermined area is protected.
The base station of the present invention can thereby be an ordinary base station of the wireless cellular telecommunication system which additionally to its usual elements comprises the generating means and the transmitting means according to the present invention whereby the transmitting means also transmits normal signalling or user data information of the telecommunication system. Alternatively, the base station of the present invention is a specialised base station with a restricted functionality compared to an ordinary base station. Depending on the required application, the specialised base station could comprise essentially the generating means and the transmitting means according to the present invention without further elements for communicating data in the telecommunication system. This last possibility would present a very simple and cost-effective way to protect certain areas according to the present invention.
The above object is further achieved by a mobile terminal for a wireless cellular telecommunication system, with transmitting and receiving means for transmitting information to and receiving information from base stations of said telecommunication system and for receiving mode change information transmitted from a base station by means of system information messages of a broadcast control channel of the wireless telecommunication system for protecting a predetermined area from disturbing usage of the mobile terminal, and control means for detecting received mode change information and changing an operation mode of the mobile terminal depending on the received mode change information so that said predetermined area is protected.
The wireless cellular telecommunication system can be any known or future system using system information messages in a broadcast control channel. System information messages are e. g. used, when a mobile terminal is switched on. The mobile terminal will then read the broadcast system information messages transmitted from a base station in a broadcast control channel. The system information messages usually contain information concerning the respective base station and the network, e. g. the timing, the channel structure, the location including the network identification and so on. According to the present invention, these system information messages are used for the transmission of mode change information to protect a predetermined area. The predetermined area is thereby the restricted area, in which the particular base station transmits the mode change information. E. g., such a predetermined area could be a hospital or a small area around the boarding gate of an airport or inside a plane.
The advantage of the described invention is that it does not rely on peoples responsibility to switch off their phones, but that it will perform this automatically. This will provide much higher safety to the areas to be protected.
Furthermore the mode change information is broadcast to each phone within the cell site, which makes sure that each mobile terminal supporting the mode change functionality will be reached and prevented from disturbing usage. However, it still can be possible to exempt mobile terminals from groups of people, e. g. security personnel, from mode change, so that these can still utilise the communication tools provided by mobile telephony.
A further advantage is that the described invention will only require a very small upgrade to existing systems and therefore additional investment in infrastructure is not necessary. All the described areas can be performed by changes to the software of the infrastructure. The impact on mobile terminals is also kept to a minimum in order to avoid any major impact on the cost of those terminals. According to the present invention, the system information message from the base station comprises, consists of or relates to mode change information for changing an operation mode of the mobile terminal.
Advantageously, the mode change information replace at least partially the system information messages in the broadcast control channel. Alternatively, the mode change information is additional information to the system information in the broadcast control channel. As another alternative, the system information messages of the broadcast control channel can comprise indicating information indicating a channel in which the mode change information is transmitted said channel being different from the broadcast control channel. In case that the mode change information replace the system information message, the base station according to the present invention can be built very simple and cheap, since it only needs to transmit the mode change information on a particular broadcast control channel. A mobile terminal switched on within the predetermined area receives the mode change information instead of or in addition to the system information message and changes its operation mode correspondingly. The predetermined area to be protected is usually within a cell or adjacent to one or more cells of the telecommunication system. A mobile terminal in one of the neighbouring cells may receive information, but not necessarily, about neighbouring base stations within the system information messages from the current base station. The channels, on which these neighbouring base stations can be found, are monitored by the mobile terminal and when the signal of the current base station becomes weaker and the signal from a neighbouring base station becomes stronger, the mobile terminal will eventually switch to the neighbouring cell. In case that the signal from a neighbouring base station is a mode change information according to the present invention, the mobile terminal will change its mode when the signal carrying the mode change information receives a certain strength, which indicates, that the mobile terminal is entering the predetermined area to be protected.
Advantageously, the transmitting means of the base station regularly transmits the mode change information. The generating means advantageously generates mode change information for switching off at least the high frequency portion of a mobile terminal receiving said mode change information. The high frequency portion of a mobile terminal, which comprises e. g. upconverting and downconverting means, is the most important part of a mobile terminal to be switched off for avoiding interference with the circuitry of other electronic or electric devices in the predetermined area.
Advantageously, it is possible to define additional information in the change mode information, which can exclude groups of mobile terminals from changing their mode.
Alternatively, the generating means generates mode change information for switching a mobile terminal receiving the mode change information into a silent mode, e. g. a ringer off or a vibrating device on mode. In the silent mode, audible or acoustic signals output from the mobile terminal are at least reduced to low volume to avoid a disturbance in the predetermined area. Advantageously, the audible signals are completely suppressed and replaced by visual signals, vibrating signals or other non-audible signals.
Advantageously, the mobile terminal of the present invention maintains the changed mode as long as the mode change information is received and detected. The mobile terminal could thereby regularly check if the change mode information is still received regularly and changes its mode as soon as the mode change information is not received anymore. The mobile terminal could further comprise a timing means for calculating the time period since the last reception and detection of a mode change information and for comparing the time period with a predetermined time threshold, whereby the mobile terminal is reset to the original mode in case that the time period exceeds the time threshold. Alternatively, the control means maintains the changed mode until a time period received as time information with the mode change information has expired, whereby the mobile terminal is reset to the original mode thereafter. In addition the mode change information may contain a minimum time indication on how long the mode change should apply.
Advantageously, the transmitting and receiving means of the mobile terminal receives the system information messages of the broadcast channel, whereby the system information messages comprise indicating information indicating a channel in which the mode change information is transmitted, said channel being different from the broadcast control channel, and receives said mode change information on the different channel.
Advantageously, the control means, upon detecting mode change information, switches off at least the transmitting part of a high frequency portion of the mobile terminal. The mobile terminal could still receive reset messages, which reset the change mode, through its receiver. However, the receiver still would emit high frequency signals which could disturb other equipment. In case that there is no requirement for reset messages the whole high frequency part of the mobile terminal could be switched off. Further, the entire mobile terminal could be switched off. Alternatively, the control means detecting mode change information switches the mobile terminal into a silent mode, e. g. a ringer off or a vibrating device on mode. As stated above, the silent mode is a mode in which audible or acoustic signals output from the mobile terminal are at least reduced in volume so that disturbance within the predetermined area is avoided. In case that the audible or acoustic signals are suppressed completely, they are replaced by visual signals, vibration signals or the like.
Advantageously, when the mobile terminal is located in a cell adjacent to the predetermined area, the transmitting and receiving means receives information on the position of the broadcast control channel of the base station according to the present invention for protecting the predetermined area, then, the control means of the mobile terminal determines the receiving power of the broadcast control channel of the base station. During a conversation the mobile terminal will report back these measurements, from which the system will realise that the mobile terminal is approaching the predetermined area and will then be able to issue a warning information, either through audible sounds, e. g. the earpiece or the ringer, or by signalling information to the mobile terminal, which will then behave according to pre-set behaviour. This means, that if the mobile terminal is in a normal telecommunication cell adjacent or surrounding the predetermined area, the system information message received by the mobile terminal from the current normal base station indicates the position of a broadcast control channel, on which the base station in the predetermined area for protecting the predetermined area transmits the mode change information. In case that the receiving power of the system information message in the broadcast control channel of the base station in the predetermined area is strong enough, which indicates that the mobile terminal is approaching or within the predetermined area, a alarm signal is output to warn the user that the mode of his mobile terminal will be changed soon. This is very helpful during a phone call. If a user using a mobile terminal is in a telephone conversation and approaches the predetermined area, in which the operation mode of the mobile terminal will be changed, he receives a warn signal and is thus able to either terminate the conversation or step further away from the predetermined area to be able to continue his conversation.